The present disclosure relates to implantation of medical devices such as prosthetic heart valves and, more particularly, to assemblies and methods for loading a device such as a self-expanding collapsible heart valve into a delivery device.
Prosthetic heart valves may be formed from biological materials such as harvested bovine valves or pericardial tissue. Such valves are typically fitted within a stent, which may be inserted into the heart at the annulus of the compromised native valve to replace the native valve. To perform such insertion procedure using a minimally invasive technique, it is typically necessary to compress the stent to a reduced diameter for loading into the delivery device.
In the case of valves formed from biological materials, the stented valve is preferably preserved in the open condition for storage as compression of the valve material for extended periods compromises the integrity of the biological valve. It is therefore necessary to crimp the valve, or reduce its diameter for loading in the delivery device, in the operating arena.
Present crimping devices and methods for collapsing a stented valve, including direct radial assemblies, have proven to be unsatisfactory as they include bulky assemblies, are difficult to master, are time consuming, impart undue stress on the stented valve, or exhibit other undesirable qualities. Moreover, it is sometimes difficult to securely engage the stent to the retaining element of a delivery device. It would therefore be beneficial to provide a device and method for collapsing a stented bioprosthetic heart valve using apparatus and techniques that overcome the deficiencies of conventional devices. In addition, such devices and methods could be useful in the loading of the collapsed stented valve into a minimally invasive delivery device.